Municipal signal system



M n d 0 M 0 m No. 588,965. vPatented Aug-.31,189'7.

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ERBATON. MUNICIPAL SIGNAL SYSTEM.

No. 588,985. Y' Patented Aug.l81, 1897.

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UNITED STATES EErcE.

PATENT IIOIVARD EATON, OF CAMBRIDGE, MASSACHUSETTS, ASSIGNOR TO MULFORDM.-DUNN, OF BOSTON, MASSACHUSETTS.

MUNICIPAL SIGNAL SYSTEM.

SPECIFICATION forming part-f Letters Patent No. 588,965, dated August31, 1897. Appiicaion filed Novembr'zt, 1888. Renewed February 1,1887.seria No. 821,552. (No model.)

To ,af/ZZ whom it may concern:

Be it known that I, HOWARD F. EATON, of

Cambridge, county of Middlesex, State of Massachusetts, have invented anImprovement in Municipal Signal Systems, of which the followingdescription, in connection With the accompanying drawings, is aspecification, like letters and figures on the drawings representinglike parts.

In a municipal telegraph system such, for instance, as lshown anddescribed in United States Patent No. 359,687, dated March 22,

1887, the special and patrol signals are transmitted from thesignal-boxes and received at the central station and an audible alarm orvindicating-signal is provided at the central station, which is,responsive to some of the signals and not others-as, for instance,responsive to the special signals only. Suitable means are shown forcarrying out the invention. In other patents other means than that shownin the aforesaid patent are shown for the attainment of the same end. I

This invention has for its object to provide a different form ofapparatus at the central station than any noW known to me, adapted tocall into operation or to operate an audible alarm or indicating-signalfor some of the signals and not others-as, for instance, for the specialsignals. A

In accordance withV this invention the signals are transmitted bychanges in the condition of the circuit, as by interruptions, and thosesignals that it is desired the alarm shall respond an additional numberof changes are effected. The signals are received at the central stationupon any suitable or Well-known form of register or other receivinginstrument, and a step-by-step device is also employed at the centralstation, which is affected by the changes in the circuit and which upona given number of changes or impulses calls into operation the audiblealarm orA indicating-signal. Meansare also provided at the centralstation for detecting a broken Wire, as will be described.

Figure l shows in diagram a signal-transmitter at one ofthe boxes andthe receiving instruments at the central station; Fig. 2, an enlargeddetail of the apparatus at the censhown comprising a series ofbreak-Wheels 1 2 3 4 5 6 and a series of contact-pens 7 8 9 10 11 12,and as elements not shown a selectingcylinder and pointer, allsubstantially as represented in United States Patent No. 320,032,

dated June 16,' 1885.

The signal-wl1eels are differently formed to transmit a different numberof impulses for the different signals.

For the regular patrol-signals signal-Wheels 1, 3, 5, and 6 are used,the Wheel 6 representing the box-number, and for the special signals, asWagon and telephone, the Wheels 2 and 4 are used, these Wheels havingthereon many notches, so that the-condition of the circuit may bechanged many times in succession.

The Wagon Wheel 4L is herein shown as provided with twelve notches and acut-away portion Which corresponds to the projecting portion of theboX-number wheel, and the telephone Wheel 2 has eleven notches precededby a short dash as a distinctive character.

As the signals are transmitted from the boxes the armature of thereceiving-relay c responds, closing a local circuitd, including a localbattery d and an electromagnet of IOO its upper end a pusli-pawl t',which is normally pressed against a guide-pin i by a spring r.

The pawl has on its under side a cam or projection which comes incontact with the guide-pin as the armaturefis moved, so as.

to move the pawl on its pivot.

The pawl when moved forward, as by the attraction of the armature,engages the teeth of a ratcliet-wlieel i3, lined to a shaft i". A signalor circuit wheel t5 is also secured to the shaft i4, which, when theshaft has been revolved a determinate distance, makes contact with thepen t6. A pawl is, having an extended slianl; portion t9, is adaptedunder the action of its spring to engage the teeth of the ratchet-wheel'i3 to insure forward motion only of the ratchet-wheel when the pawl isin engagement; but when the armature is retracted from the poles of themagnet e the upper end of the bar f strikes the shank portion i9 anddiseiigages the pawl from the ratchet-wheel 3. A cord (see dotted lines)passes around the shaft i4, to which is attached a weight @'10, so thatwhen the ratchetwheel is disengaged by the pawl t8 it will be restoredto its normal position.

In operation when a wagon-signal is transmitted twelve impulses aretransmitted in succession, and the bar f will be moved upon theoccurrence of the first impulse, so that its pawl t' will engage andmove the ratchetwheel 'i3 forward one step. The time which elapsesbetween the several impulses is not sufficient for the armature toresume its normal position, and hence vibrates in a limited field beforethe poles for the several impulses, and each impulse feeds theratchet-wheel forward one step. The box-number follows this series ofshort impulses, but a sufficient interval of time elapses previous tothe boxiiuinber for the armature to return to its normal position, andcauses the upper end of the bar f to disengage the pawl i. vlVhen theratchct-wlieel is has been moved upward a definite distance step bystep, the circuitwheel t5 closes a local circuit 15, containing thelocal battery 16, the magnet 17 for an annunciator-drop, and the magnet18 for a bell, so that a bell will be sounded for all signals which haveas a part of them a large series of short impulses. rlhe bell 18 hereinshown constitutes one form of a special indicating device actuated bythe series of short impulses. I have also'herein shown a creepercomprising a segment n and milled wheel n', said segment operating tolift the pen 'n2 in contact with the pen n3, as upon the occurrence of along dash, such as might be caused by a broken wire, to thereby closethe local circuit n4, containing the local battery n.5, the magnets n ofan annunciator-drop, and the magnet ni of a bell.

I do not desire to limit my invention to the precise construction hereinshown for carrying out this invention, as it may be changed in many waysand yet accomplish the result which forms the essential feature of thisinven tion.

In Fig. 3 the armature of the electromagnet c is shown upon the oppositeside of the barf, so that the said inaguet maybe included directly inthe main circuit in eontradist'inction to being placed in a localcircuit, as shown in Fig. 2.

I do not claim the ereeper herein shown.

I claim- 1. In a municipal telegraph system coinprising a centralstation and several substations connected by an electric circuit, amultiple-signal transmitter at each substation constructed and arrangedto transmit a series of impulses constituting the substation-number andadapted at times to transmit another long seiies of short successiveimpulses, coinbined with a register to receive the signals transmittedby said transmitters, and a special indicating device unaffected by oneof the series of impulses but affected by the long seiies of shortsuccessive impulses, substantially as described.

2. In a municipal telegraph system comprising a central station andseveral substations connected by an electric circuit, a multiple-signaltransmitter at each substation constructed and arranged to transmit aseries of impulses constituting the substation-number and adapted attimes to transmit an' additional long series of impulses, combined witha register to receive the signals transmitted by said transmitters, anda special indicating device unaiiected by the series of impulsesconstituting the substation-number but affected by the additional longseries of short successive impulses when the latter are transmitted inconjunction with the substation-number, substantially as described.

3. In a municipal telegraph system comprising a central station andseveral substations connected by an electric circuit, themultiple-signal transmitters at the substations for transmitting inconjunction with some of the signals several regular impulses, combinedwith a register for the signals, the electromagnetically-movablecircuit-wheel 5, a bell, the circuit of which is controlled by saidwheel the creeper n, wheel a', and the bell controlled by it,substantially as described.

4. In a municipal telegraph system comprising a central station andseveral substations connected by an electric circuit, multiple-signaltransmitters at the substations constructed and arranged for producingin conjunction with some of the signals a large number of impulses iusuccession, combined with a register for receiving the signals, and withan electroinagnetically-inovable circuitehanging device comprising themagnet c, its armature, and bar f, a pawl carried by it, the cscapementfor rctarding the movement of the bar f, and the ratchet-toothed wheeland circuit-wheel 5, and bell in circuit controlled by saidcircuit-wheel, substantially as described.

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1o it, the escapement for retarding the movement of the bar f and theratchet-toothed wheel and circuit-Wheel 5, substantially as described.

In testimony whereof I have signed my name to this specification in thepresence of I5` two subscribing Witnesses.

HOWARD F. EATON.

Witnesses:

JAS. H. CHURCHILL, FREDERICK .L. EMERY.

